Chapter 3 Flashcards
(17 cards)
Deductive arguments:
Intended to provide logically conclusive support for its conclusion
Deductively valid:
A deductively valid argument means that if the premises are true, then the conclusion MUST be true
E.g. (Premise] All Canadian police officers carry a gun. [Premise] Alexandra is a Canadian police officer. [Conclusion] Therefore, Alexandra carries a gun.
Inductive arguments:
the premises are intended to provide probable, not conclusive support for its conclusion
if the premises are true, then the conclusion is PROBABLY or LIKELY to be true
Deductively sound:
If it is valid, and has true premises
Inductively strong:
Succeeds in providing probable support for its conclusion
Inductively cogent:
Strong argument, and has true premises
Principle of charity:
If we find someone’s argument unclear, we should attempt to interpret it in a way to make it make sense.
Which types of arguments are said to be “truth preserving”?
Valid deductive arguments
A deductively valid argument can also have true or false premises and true or false conclusions
True or false
True, validity is based on the structure.
True or false:
A valid argument cannot have true premises and a false conclusion.
True, in a valid deductive argument, if the premises are true, then the conclusion MUST be true
Affirming the antecedent (modus ponens)
If p, then q.
P.
Therefore, q
Hypothetical syllogism:
if p, then q.
if q, then r.
Therefore, if p, then r.
Denying the consequent (Modus tollens)
If p, then q.
Not q.
Therefore, not p
Denying the antecedent:
If p, then q.
Not p.
Therefore, not q
Affirming the consequent:
if p, then q.
q.
Therefore, p
Disjunctive syllogism:
Either p or q.
Not p.
Therefore, q.
What are the 2 argument pattern forms which aren’t valid
1- Affirming the consequent
2- Denying the antecedent
